mysql 根据总分排名

mysql 根据总分排名

SELECT
    t.*,
    @rank := @rank +  AS rank
FROM
    ( SELECT @rank :=  ) r,
    (
SELECT
    tas.id,
    tas.teacher_id,
    tas.average,
    tas.remark,
    tas.create_time,
    tas.course_id,
    su.user_name,
    ti.post,
    ti.SUBJECT
FROM
    teacher_average_score tas
    LEFT JOIN sys_user su ON tas.teacher_id = su.user_id
    LEFT JOIN teacher_info ti ON tas.teacher_id = ti.user_id
ORDER BY
    tas.average DESC
    ) AS t

mysql数据库查询表中相邻数据的差值

select a.time ,a.sum - b.sum sum,a.time,b.time
from
(select @arownum:=@arownum+ rownum,sum ,time from summary_hour,(select @arownum:=) t where energy_type=  order by time) a,
(select @brownum:=@brownum+ rownum ,sum,time from summary_hour,(select @brownum:=) t where energy_type=  ORDEr by time) b
where a.rownum = b.rownum;